6 PPC vs 6 WOA

[subsonic]

Since these two cartridges are simular in size, I was curious if I could use the 6 PPC load data as a starting point for my 6 WOA? I have an 8 twist barrel that's 26" long. I will be shooting 70gr Sierra and 95gr Berger out to 600 yards.

 

[spclark]

They're not as similar as you might want to think.

You'd be better off giving John Holliger a call once he gets back from Camp Perry this week & ask his advice.

Here's a ink to posts on this forum from some months back that may also help you some:

http://www.accurateshooter.com/forum/index.php?topic=3745744.0

 

[Longone]

This may help also.

http://iowahighpower.com/6mmwoa/index.php

LG

 

[subsonic]

spclark, you're right I checked the measurements and the 6WOA is larger and obviously has more case capacity than the 6PPC's 1.99cc of useful case capacity. I might be incorrect but it looks to me the 6WOA is closer to the 6BR's 2.18cc of useful case capacity [according to info printed in the Lee reloading manual]. Do you have any idea what the useful case capacity is for a 6.8SPC cartridge?

 

[spclark]

Not off the top of my head, but John's suggestion to start with 6BR loads for the 6HAGAR upper he chambered for me would make me conclude the 6.8SPC cartridge is somewhat less in case volume. His 6WOA has the shoulder pushed back slightly, so ought to hold even less.

The 6HAGAR is a slightly longer cartridge & can't be made from 6.8SPC parent brass as a result.

More frequently case volume is measured in grains of water capacity. Water weighs 1.0 gram / cc. Wikipedia tells me 1 gram = 15.432 grains, so your 2.18 cc = 33.64 grains for a 6BR, the 6PPC would be 30.71 grains.

Some informal results posted for the 6BR suggest ~ 39 grains so there's an error factor there somewhere to be aware of... perhaps when comparing filled-to-the-brim numbers with filled-to-the shoulder?

One of my fired 6HAGAR cases holds 32.55 grains water when filled to about where my 600 yard load stops; filled to the top of the neck it's 39.75 grains or pretty close to what John indicates. (I had a 6WOA fired case around somewhere but couldn't locate it for comparison when I checked one of my fired 6HAGAR cases.)

Your best bet would be either to start with slightly reduced loads suggested by other 6WOA users or contact John directly for his recommendations.

 

[subsonic]

spclark, I followed the Wikipedia formula and came up with 1.91cc of water up to the shoulder = 29.48gr and 2.31cc to the brim = 35.65 in a unfired case. So I loaded the case up to the shoulder with Varget and it measured out to 25.5gr. With a Sierra 70gr HPBT Match bullet seated to 2.258, I still have space for more powder. With the same load of Varget and a Nosler 80gr Spitzer seated to the same depth [for a magazine feed AR] it seems to be close to a compressed load. I emailed John Holliger and he said "just add powder till the primers fall out and back off 1/2 grain"...........the load data sheet he sent me shows powder weight for all loads start at 25.0gr and end at 30.0gr for light bullets and 29.5gr for the heavy bullets.

 

[DanCarey]

First let me say, I think the 6WOA is the cream of the crop in an AR 15. I have used mine for the last 4 years on predators and varmints with outstanding success compared to a 223. My predator load is 29 grains of Benchmark and a Hornady 65 grain bullet at 3400 FPS. They will shoot under 1/2" just about anytime. The rifle has a 1-10 twist so its limited to the same bullet you can use in a standard 243 Win.

 

[subsonic]

spclark, mine has a 1:8 twist inside a 26" SS tube. I will be using 70gr Sierra in SSA brass [small primers]. I received some data from site member dfry in another post but I have been so busy that I have not had a chance to shoot my 6WOA which I put together over a month ago. I put together some rounds starting at 25.0gr of Varget to break in the barrel and then work up to a load starting at about 26gr until I see sign of high pressure. I was just wanding if there was another cartridge out there that might be comparable to the 6WOA.

 

[spclark]

6HAGAR for one, there's a 6mmPDK from another Illinois source, both derived from the 6.8SPC case parentage (though the 6HAGAR requires .25 or .30 Remington brass, which is where the 6.8 SPC also began!).

John H. can build you an upper chambered in any one of these or his 6WOA & they'll all shoot just fine.

Then there's the 6"Grendel" more commonly known as Robert Whitley III's 6mmAR and 6mmAR Turbo.

Also one called 6RAT, which uses 6.5 Grendel brass too.

I believe John's equipped to chamber for the latter; you'll have to go to RCWIII to obtain the others.

Good luck & good shooting with your 6WOA!

 

[dfry]

8ball, did you ever get a chance to try your 6WOA? Was curious where you are at. From this post, it looked like your 70SMK loads with Varget are way light. Also, John in general suggests using the 6PPC top loads for any given bullet as a starting point for the 6WOA. This of course depends on the case you are using. This technique worked for me with all bullet weights up to the 107SMK and 108 Berger where for some reason I am below the 6PPC max load with Varget. I am at 27 grs. of Varget for a 107 or 108 in R-P brass and at 27.5 grs. of Varget with those same bullets in the SSA brass. Dave

 

[constructor]

I have a 6X41 based on a shortened SPC case with a 30 degree shoulder so I can shoot 95 and 107 smks from the mag. 27gr N530 with 95SMKs produce 2836fps from an 18 3/4" barrel.
27gr varget is close but much more compressed and accuracy suffered as a result.

 

[subsonic]

I have only had my 6WOA out once and started with 25gr RL15 with the 70gr SMK and got to a max load of 29gr RL15. I felt that the 29gr load was a bit light myself. Just as soon as I get my die back from Redding, I plan to do more loading. I will start with the max 6PPC data and work up. I most say so far the 6WOA is very accurate.

 

[mc223]

I sure was glad to see 6 WOA on this forum again. Hello spclark and Dave. Welcome to the OP. I havent been here for a while.
I dont have my load book handy, but as John H said load them till you lose a primer then backoff a half.
If you search the old forum here, there may be some of my original test stuff. Just search under mc223 and good shootin.

 

[subsonic]

Hey guys, since I am not shooting from a mag with my 6WOA, can someone suggest a good starting point with bullet setting depth? I have 70gr SMK, 80gr Nosler BT, 87gr Hornady V-max and 107gr SMK's.

 

[dfry]

The 107s .020" off the lands, the rest I load to mag length. you need to check the bullet jump on the 87s, the rest will not be close enough to worry about. You need to have them seated at least deep enough to hold the bullet in the neck. Dave

 

[gzig5]

How much Varget are you able to run with the 105-108s in SSA brass in your 6WOAs? I've got a WOA upper in 6mmPDK that I've shot the last two years with zero load development, just threw what seemed like a safe load and went with it. Works pretty well but I think I'm on the light side and should be a grain or two above the 6WOA. I figured out at the end of last season that the 6mmPDK chamber neck is a little tight for SSA brass, so I get to turn some necks this winter.
Greg

 

[dfry]

Greg, most shoot about 28 grs. of Varget in the SSA brass. I can't shoot that much without loosing the primers in 2 firings. I have to shoot 27.5 grs. of Varget in the SSA brass. I shoot 27 or 27.1 in the R-P brass. What is your case capacity with the PDK? the SSA brass for the 6WOA is 35 grs. of water. What velocity are you getting with the 107s in the PDK. I shoot about 2700 fps, anymore and I loose primer pockets to quickly. Those shooting moly seem to have better luck with the brass, but I hate moly, Dave

 

[gzig5]

I've run up to 28gr Varget with moly'd 107s and I shoot 28 with the 87gr BTHP, but those loads were only a guess. I've done no load development yet. But, I found out that the SSA brass has thick necks and only leave .001" clearance on a loaded round in my chamber. Everything shot well, but a bullet wouldn't go back in a fired case. I'm lathe turning the necks to give me a .269 loaded diameter in my .273 neck chamber. I just checked with some BLC-2 and a fired 6PDK case will hold 36.3 gr to the top of the neck and about 32.4 to the base of the neck. I don't have 6WOA to check against. I don't think the volume increase is large but as I understand it, the shoulder diameter is bigger (less taper) and the shoulder is moved forward a bit compared to the 6WOA. I have the chamber print if someone can come up with the 6WOA print to compare against.
Greg

 

[dfry]

All I have is a reamer print, also I sent a reply to your personal message, Dave